File:Bulletin (1971-) (20235466458).jpg

Title: Bulletin
Identifier: bulletin7477sout (find matches)
Year: 1971- (1970s)
Authors: Southern California Academy of Sciences
Subjects: Science; Natural history; Natural history
Publisher: Los Angeles, Calif. : The Academy
Contributing Library: New York Botanical Garden, LuEsther T. Mertz Library
Digitizing Sponsor: The LuEsther T Mertz Library, the New York Botanical Garden

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252 BULLETIN SOUTHERN CALIFORNIA ACADEMY OF SCIENCES VOLUME 75
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Figure 1. Ventral view of the maxillary segment of the teiid lizard skull A) Kentropyx, B) Neiisticuiiis, and C) Bacliia. Not drawn to scale; exo, fenestra exochoanalis: int. internal nares; Jac, opening of Ja- cobson's organ; inf, inferior orbital foramen. well developed secondary palate (Romer, 1956) but among living forms only the crocodilians and some turtles and lizards possess such a structure. Camp (1923) commented on the contact of the pterygoids in the midline of the palate in scincids and agamids. Goodrich (1930) referred to the secondary palate as a false palate when describing the structure in croco- dilians. JoUie (1960) described the elements associ- ated with the palate in lizards but failed to mention the presence or absence of a secondary palate in the groups he examined. Greer (1970) described the secondary palate in scincids and stated that this char- acter was a diagnostic feature of the family. The shape and arrangement of the palatines and ptery- goids which are involved in the formation, are use- ful in recognizing subfamilies and taxa of lower rank among the scincids (Greer, 1967a, 1967b; Greer and Parker, 1968). MacLean (1974) reported on the presence of a secondary palate among many genera of the subfamily Gymnophthalminae (Family Tei- idae), but did not describe, in detail, the structure or form that it takes in those genera. In lizards the elements which may contribute to the secondary palate are the vomers, maxillae, pterygoids and the palatines. The vomers are paired, flat plates that articulate with the medial palatal process of the maxillae and the premaxillary anteriorly and with the palatines posteriorly. The vomers do not contact the pterygoids. Among the majority of lizard gen- era there is an elongated fenestra, the fenestra exo- choanalis. between the medially positioned vomers and the lingual shelf of the maxillae (Fig. lA). This long fenestra, forms posteriorly, the opening of the internal nares into the mouth cavity and, anteriorly, provides a foramen for an entrance to Jacobson's organ. The structural elements involved in the formation of the secondary palate in microteiids, based on my observations, include the maxillae and vomers. The palatines form a posteriorly oriented groove dorsal and lateral to the internal nares. The pterygoids do not play a role in the formation of the structure as in scincids. Within the microteiid genera two structural condi- tions of the secondary palate can be recognized. MacLean (1974) reported that Alopoglossus Cerco- saiira, Colobodactylits. Ediinosaura and Gymnoph- tlialnms possessed a secondary palate. To that list I am adding Ecpleopiis, and Heterodactyliis. In these genera maxillae form a complete lingual shelf that contacts the slight expanded vomers medially, elimi- nating the fenestra exochoanalis. The vomer extends anteriorly, contacting the premaxillary. The presence of an anterior foramen in the maxillae-vomer suture leads to Jacobson's organ (Fig. IB). The internal nares exit in the posterior portion of the mouth cavity medially to the position found in nonsecondary palate forms. The vomers are antero- ventral to the external nares. A groove on the ven- tral surface is formed by the ventral surface of the palatine bones. The internal nares are bordered by the vomers, anteromedially and anteroventrally and by the palatine bones dorsally and dorsolaterally. In Bachia (Fig. IC) the maxillae do not contribute an expanded flange to the lingual shelf. The shelf is formed by an anterolateral process of the palatines

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